No real advice, but commiseration here. My ds (3 years old) started out doing the same thing about a year ago, and now, he sometimes even hits one of us (if he's w/in striking distance) if we start a conversation in his presence. We have talked with him about how he should say, "Excuse me" if we are conversing and he would like to get our attention, but only rarely does he use those words. Usually, he wants our attention directed toward him for no specific reason. We tell him to wait one second, and we keep our conversations as brief as possible. That doesn't help you, I know...I'll read as people respond cuz I need help in this department!